Differences between single, singleordefault, first, and firstordefault in C #

Single (condition): It is determined that only one value meets the condition results; otherwise, an error is returned, if there are multiple values, the sequence contains more than one matching element is reported. If no matching element exists, the sequence contains no matching element is reported.

Singleordefault: Only one or zero value is allowed under the specified conditions. If more than one value meets the conditions, an error is returned.

First (condition): If the condition is determined, there must be at least one value. Otherwise, the sequence contains no matching element error is returned.

Firstordefault (condition): If the condition is determined, there can be 0 and more values.

 

Int [] Nums = {1, 2, 4, 8, 16, 32, 64,128,256,512,102 4}; console. writeline ("Single:" + nums. single (x => x> 4 & x <9); console. writeline ("singleordefault:" + nums. singleordefault (x => x> 4 & x <7); console. writeline ("First:" + nums. first (x => x> 4 & x <512); console. writeline ("firstordefault:" + nums. firstordefault (x => x> 513 & x <512 ));
 

Differences between single, singleordefault, first, and firstordefault in C #